Ribbon change apparatus

ABSTRACT

A vibrator-ribbon guide connecting structure is provided for facilitating coupling thereto of a ribbon guide through which a ribbon is prethreaded whereby quick and clean ribbon changing may be accomplished. The ribbon guide and vibrator are so associated that the ribbon guide is freely removable from the vibrator when the vibrator is at rest yet is positioned to be elevated and positively retracted by the vibrator during vibrator movement.

United States Patent Frechette et a1.

RIBBON CHANGE APPARATUS inventors: Thomas E. Frechette, Windsor Locks;Daniel J. Rosborg, Bristol, both of Conn.

Litton Business Systems, Inc., New York, N Y.

Filed: Feb. 21, 1974 Appl. No.: 444,708

Assignee:

U.S. Cl 197/170; 197/159 Int. Cl. i B41J 35/04 Field of Search 197/151,157-159, 197/170, 154

References Cited UNITED STATES PATENTS 8/1941 Johnson 197/170 X 1 Sept.16, 1975 2,518,893 8/1950 Huether 197/170 2,919,784 1/1960 Morris197/159 3,302,766 2/1967 Page 197/159 X Primary Examiner-Clifford D.Crowder Assistant Examiner-R. T. Rader Attorney, Agent, or Firm.losephR. Spalla 5 7 ABSTRACT 10 Claims, 4 Drawing Figures PATENTE SEP 1 5 r975RIBBON CHANGE APPARATUS This invention relates to ribbon mountingstructures for typewriters or like business machines to facilitateribbon changes; more particularly,- it relates to vibrator elevatorstructure which is freely receivable within an opening in a ribbon guidemounted on a ribbon; and specifically it relates to a vibrator elevatorstructure which expands into the'opening in the ribbon guide duringoperative movement-thereof.

Problems in providing clean quick change of ribbons in typewriters orlike machines arise from the fact that the ribbon must be threadedthrough ribbon guides associated with a vibrator which raises and lowersthe ribbon opposite the print point incident to each type action.Various solutions to this problem have been presented including ribbonguides which facilitate the manipulation of a new ribbon into the guideforming part of the vibrator mechanism. Still, even with a nimbleoperator, quick ribbon changes are not possible. Still other solutionshave separated the ribbon guide from the vibrator and prethreaded theribbon on the ribbon guide. In these structures, the ribbon guide isdesigned for reception by vibrator elevator structure associated withthe machine. U.S. Pat. Nos. 2,252,075 (Johnson); 2,518,893 (Huether);and 2,873,015 (Gray) are exemplary of these prior art solutions. InHuether, the ribbon guide is detentably secured to and removable fromthe vibrator elevator structure through application of manual force. Theapplication of force may subject the vibrator structure to damage andthe repeated insertion of new ribbon guides subject the vibratorstructure to wear. In the Johnson and Graypatents, the ribbon guidemerely rests on the vibrator structure and after being raised returns bygravity in Gray or by springs in Johnson. 7

In that the vibrator must raise a ribbon opposite the printing lineincident to and before a type bar strikes and returns, the ribbon guidesof Johnson and Gray are likely to become disengaged from and not followthe movements. of the vibrator structure due to the accelerating forcesor friction and not work properly.

In accordance with the present invention, the disadvantages of the priorart are overcome in the provision of a vibrator elevator'structure whichis freely receivable in an opening of a ribbon guide structure throughwhich a ribbon is prethreaded to facilitate mounting and removal of theribbon guide from the vibrator structure without application of force,yet which during elevating and retracting movement of the vibratorelevator structure is engaged with and carried by the vibratorstructure. More particularly, a vibrator elevator structure is providedhaving a ribbon guide coupling end which expands incident to elevatingmovement to engage the walls of a receiving opening provided in a ribbonguide.

An object of the invention is in the provision of a clean quick changeribbon structure.

Another object of the invention is in the provision of a ribbonguide-vibrator coupling structure to facilitate ribbon changes.

Another object of the invention is in the provision of a ribbonguide-vibrator coupling structure which is freely separable in quiescentstate and positively engaged in active state. i

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following detailed description when considered inconnection with the accompanying drawing in which like referencenumerals designate like or corresponding parts through thefiguresthereof and wherein:

FIG. 1 is an elevational view of a prethreaded ribbon guide operativelyassociated vibrator elevator structure in restposition;

FIG. 2 is a view similar to FIG. 1 with the parts in elevated position;

FIG. 3 is a perspective view of the vibrator structure;

and I FIG. 4 is a perspective view of another ribbon guide embodiment.

With reference now to the drawing wherein like reference charactersdesignate like or corresponding parts throughout the several views thereis shown in FIG. 1 a ribbon 10 prethreaded through a ribbon guide meansgenerally designated by reference numeral 11 adapted to be mounted forvertical elevating movement at a print point location. As will beappreciated by persons skilled in the art, the prethreaded ribbon 10 maybe spooled on spools mounted on either side of a printing point, or,alternat ively, on spools located to one side of the machine print pointwith the ribbon running to the printing point and back via a tum-aroundprethreaded ribbon guide. In either case, the ribbon guide means 1 1 maybe slidably supported in a rigid ribbon guide structure extending to theprinting point from the spool location. In the embodiments shown, theribbon guide means 11 areadapted to be mounted on vibrator structurevertically. With particular reference to FIG. 3, one embodiment ofribbon guide means 11 comprises upwardly extending spaced ribbon guideforks generally designated by reference 12 which may take any form. Theguide forks 12 are provided with openin s 13 through which the ribbon 10is prethreaded. The ribbon forks 12 extend from a common lower end 14which as best seen in FIG. 1 is provided with a rectangular recess 15with a restricted opening 16 to the A lower edge 17T defining inwardlydirected internal shoulders 18.

, The ribbon guide means in the embodiment shown in FIGS. 1-3, belowguide forks 12 is formed with bent out ears 19 which are adapted toembrace and be slidably guided by conventional type guide structuregenerally designated 21 when the ribbon guide is operatively mountedthereon. The type guide structure 21 is secured to a type bar segment(not shown) as is conventional.

As viewed in FIGS. 13, the ribbon guide means 11, is associated withvibrator elevator means in the form of a rod.22 pivoted in machine sideframes (not shown) which is bent to form an eccentric bar 23 parallel tothe pivots of the rod 22. As will be understood, the rod 22 will beoscillated, as by a crank (not shown), about its pivots with the resultthat the eccentric bar 23 will swing through an arc. The vibratorelevator structure further comprises a first vertically extending arm 24which is secured to the eccentric bar 23 as by wrap around tabs 25 and26 formed at its lower end with tab 25 wrapped loosely around the bar 23and tab 26 partially therearound so as to permit limited pivotingmovement of the arm 24 with respect to the bar 23. A shouldered pivotpin 27 mounted on arm 24 pivotally secures a second upstanding arm 28 toand forwardly of the first upstanding arm 24. An arm guide bracket 30supported on part 31 of the typewriter frame is provided which extendsupwardly and forwardly with the uppermost forward extension 32 as bestseen in FIG. 3 having a guide opening 33. Also extending from the framepart is an upstop 29 located in the path of the eccentric bar. Both arms24 and 28 extend upwardly through the opening 33 with the face of theforward arm 28 guided by the forward edge 34 of the opening and the rearface of the rear arm 24 by the face 35 of the intermediate upward run 36of the bracket thus precluding movement of the arms out of a verticalplane. The arms 24 and 28 are also held with their upper oppositelyoutwardly facing edges 37 and 38 against the side edges 41 of the guidebracket opening 33 by a spring 42 wrapped around the pivot pin 27 havingone end 43 bent aboutthe edge of arm 24 and the other end 44 bent aroundthe edges of a lateral projection 45 of the other arm 28. As will beappreciated, the arms 24 and 28 are mounted scissor fashion and biasedto an open position by the spring 42. As viewed in FIGS. 1 and 2, leftedge of the rear arm 24 immediately below the upper forward slottedextension 32 of the bracket is flared outwardly forming a cam edge 46and the right edge of the forward arm 28 immediately below the extension32 is flared outwardly forming a second cam edge 47. Thus, as thevibrator elevator structure is raised, the action of the cam edges 46and 47 on the side edges 41 of the guide bracket opening 33 pivotallycam the arms toward one another about their pivots. As viewed in FIG. 1,the upper terminal ends of both arms 24 and 28 are freely received bythe recess opening 16 and are adapted on elevation to engage the upperwall 48 of the recess to elevate the ribbon guide means 11. The upperends of the arms 24 and 28 located within the recess are further formedwith oppositely facing projections 51 and 52 with the result, as shownin FIG. 2, that when the vibrator structure is elevated the terminalends are moved toward one another past overlap toward inner side wallsof the recess with the projections 51 and 52 overlying the shoulders 18of the recess opening. Thus, in this expanded crossover state, relativevertical movement between ribbon guide and vibrator arms duringelevation of the ribbon guide under push of the vibrator arms isprecluded by the interposition of projections 51 and 52 over shoulders18. The interposition of projections 51 and 52 with shoulders 18 alsoserve to positively retract or lower the ribbon guide means 1 1. Whilethe terminal upper ends of the arms are shown as extending into therecess, it is also within the scope of the invention to support theribbon guide as by abutments 53 on the type guide 21 located in the pathof ears 19 and to locate the terminal ends of the arms below the recesswith initial upward movement moving the terminal ends of the arms firstinto the recess and then causing their expansion in the recess ashereinbefore described. In such a modification. the cam edges 46 and 47would be formed lower relative to guide bracket extension 32.

With reference to FIG. 4, there is shown another embodiment of ribbonguide means generally designated by reference 55 preferably of moldedplastic couplable to vibrator elevator structure in the same manner asdescribed with reference to FIGS. 1-3. In this embodiment, the ribbonguide means 55 is assembled with, supported by and slidably mountedforelevating movement within a window opening 56 in ribbon guide structuregenerally designated by reference 57 rigidly attached to ribbonspoolhousings located=to either side of a print station. The ribbon guidestructure 57 comprises spaced walls 58 and 59 between which a ribbontracks, with the front side of the front wall 59 provided with formedlugs 62 to'embrace the type guide-whereby the Window opening of guidestructure 57 may be located at the machine print point and with therecess opening in the ribbon guide means positioned to receive thevibrator arms 24 and 28.

In this embodiment, slotted ribbon forks designated by referencenumerals 63 are integral with the common recessed end 14 adapted toreceive the vibrator arms 24 and 28. Both slotted ribbon forks 63have aright angled offset 64 which when assembled with the guide structurerests on the lower edge 65 of the window opening. Each fork 63 furtheris formed with lugs 66 which when assembled with the guide structure 57are slidably received between the walls 58 and 59 of the guidestructure. Each of the guide forks 63 are formed with offset ribbonaccommodating vertical slots 67 and 68 and is also formed with ribbonthreading horizontal slots 69.

FIG. 4 shows two guard lugs 70 and 71 located on the ribbon guidestructure 57 to either side of the common ribbon fork section 14 whichserve to protect the ribbon fork when the assembly is mounted on themachine between the type guide and a platen.

The invention claimed is:

1. In a typewriter having a frame,

a ribbon, I

ribbon guide means through which said ribbon is prethreaded,

vibrator means supported on said frame,

means for elevating said vibrator means, and

means on said guide means and said vibrator means for coupling saidguide means and vibrator means when typing,

said means comprising a recess in said guide means and means on saidvibrator means freely extendable into said recess and engageabletherewith as said vibrator means is elevated when typing.

2. In a typewriter as recited in claim 1, wherein said means extendableinto and engageable with said recess comprises at least one arm coupledto said vibrator elevating means, means holding said arm to a positionfree of said recess, and responsive to elevating movement for effectingengagement of said arm with said recess.

3. In a typewriter as recited in claim 2, wherein said holding meansincludes a slot through which said arm extends, a spring biasing saidarm into engagement with said slot, and cam means on said am cooperativewith said slot for moving said arm into engagement with said recess.

4. The typewriter recited in claim 1 wherein said means for elevatingsaid vibrator means is adapted to position said ribbon at a printingline, and wherein said means on said vibrator means freely extendableinto said recess engages said recess so that said ribbon is positivelyretracted from said printing line when said vibrator means is lowered.

5. In a typewriter as recited in claim 4, wherein said means extendableinto and engageable with said recess comprises a pair of arms, one ofsaid anns being coupled to the vibrator elevating means, the other ofsaid arms overlying said one arm and pivoted thereto scissor fashion,means to position said arms relative to one another whereby the endsthereof are free to enter said recess in said guide means, and means onsaid arms and said typewriter frame for moving said arms into engagementwith said recess as said vibrator means is raised.

6. A typewriter as recited in claim 5 wherein said means to positionsaid arms relative to one another includes spring means biasing saidarms.

7. In a typewriter as recited in claim 6, said means for moving said arminto engagement with the recess comprises cooperating camming surfaceson at least one of said arms and associated with said typewriter framefor moving said arms relative to said frame.

8. A typewriter as recited in claim 7, wherein said cooperative cammingsurface associated with said frame comprises an edge of a guide slotthrough which said ribbon guide means to lower said ribbon guide means.

1. In a typewriter having a frame, a ribbon, ribbon guide means throughwhich said ribbon is prethreaded, vibrator means supported on saidframe, means for elevating said vibrator means, and means on said guidemeans and said vibrator means for coupling said guide means and vibratormeans when typing, said means comprising a recess in said guide meansand means on said vibrator means freely extendable into said recess andengageable therewith as said vibrator means is elevated when typing. 2.In a typewriter as recited in claim 1, wherein said means extendableinto and engageable with said recess comprises at least one arm coupledto said vibrator elevating means, means holding said arm to a positionfree of said recess, and responsive to elevating movement for effectingengagement of said arm with said recess.
 3. In a typewriter as recitedin claim 2, wherein said holding means includes a slot through whichsaid arm extends, a spring biasing said arm into engagement with saidslot, and cam means on said arm cooperative with said slot for movingsaid arm into engagement with said recess.
 4. The typewriter recited inclaim 1 wherein said means for elevating said vibrator means is adaptedto position said ribbon at a printing line, and wherein said means onsaid vibrator means freely extendable into said recess engages saidrecess so that said ribbon is positively retracted from said printingline when said vibrator means is lowered.
 5. In a typewriter as recitedin claim 4, wherein said means extendable into and engageable with saidrecess comprises a pair of arms, one of said arms being coupled to thevibrator elevating means, the other of said arms overlying said one armand pivoted thereto scissor fashion, means to position said armsrelative to one another whereby the ends thereof are free to enter saidrecess in said guide means, and means on said arms and said typewriterframe for moving said arms into engagement with said recess as saidvibrator means is raised.
 6. A typewriter as recited in claim 5 whereinsaid means to position said arms relative to one another includes springmeans biasing said arms.
 7. In a typewriter as recited in claim 6, saidmeans for moving said arm into engagement with the recess comprisescooperating camming surfaces on at least one of said arms and associatedwith said typewriter frame for moving said arms relative to said frame.8. A typewriter as recited in claim 7, wherein said cooperative cammingsurface associated with said frame comprises an edge of a guide slotthrough which said arms extend.
 9. A typewriter as recited in claim 8,wherein said ribbon guide recess has a restricted opening forminginternal shoulders and wherein the ends of said vibrator arms havelaterally extending projections engageable with said shoulders operativeto lower said ribbon guide means.
 10. A typewriter as recited in claim 9having further cooperative camming surfaces which engage and move saidarms to allow said projections on the ends of said arms to therebyengage said shoulders formed on the ribbon guide means to lower saidribbon guide means.